If you think you are beaten, you are.
If you think you dare not, you don’t.
If you’d like to win, but think you can’t,
It’s almost a cinch you won’t.
Life’s battles don’t always go
To the stronger or faster man;
But sooner or later the man who wins
Is the one who thinks he can.

I don’t know who wrote this old poem but I’ve found it very true. One of the major lessons life has taught me is that nothing is impossible – some things just take a lot more faith and determination.